Fuel injector nozzle



Sept. 27, 1955 J. A. LAUCK FUEL. INJECTOR NOZZLE Filed Sept. 28, 1951 M N g w V M [nz/entr/ United States Patent assignor to Borga corporation of This invention relates to a fuel injector nozzle and more particularly to a fuel injector nozzle for use in a direct fuel injection system.

Fuel injector nozzles are essential in fuel injection systems in order to provide the atomized mist or spray of fuel requisite for proper distribution of the fuel in the burning chamber or engine cylinder chamber. Heretofore, nozzles which would provide the requisite fuel distribution have been unduly complex and therefore ex pensive to manufacture. Furthermore, many prior art nozzles are subject to clogging due to the restricted orifice generally required in such nozzles.

An object of the present invention is to provide a new and improved fuel injector nozzle.-

A further object of the present invention is to provide a more eflicient nozzle for a fuel injection system so that maximum atomization and distribution of the fuel is provided and at the same time the device be both economical to manufacture and relatively free of clogging.

In accordance with one embodiment of this invention, a fuel injector nozzle may comprise a two-piece nozzle housing of generally cylindrical configuration having formed therein at one end a discharge port through which fuel may be emitted and at the other end thereof an inlet port which may be connected to a suitable fuel source. Within the housing there is provided a valve seat and an axially shiftable valve which cooperates with said valve seat to prevent return flow through the valve from the outlet port to the inlet port. A valve stem member integrally formed with said valve member extends axially into the discharge port, to provide an annular discharge orifice, the stem member being substantially smaller than the discharge port opening, and is provided with a peripheral groove whereby the flow of fuel through the port is interrupted to provide increased turbulence. Spring loading means are provided for holding the valve normally closed.

Other objects and advantages of the present invention will be apparent from the following detailed description thereof taken in conjunction with the drawings wherein:

Fig. 1 is an axial, sectional view of a fuel injector nozzle constructed in accordance with one embodiment of this invention and mounted on an engine block;

Fig. 2 is a transverse sectional view taken substantially along the line 22 of Fig. 1; and

Fig. 3 is a fragmentary detail view showing the posi tion of the stem groove with respect to the nozzle tip dur- 7 ing injection.

The nozzle of this invention is intended particularly for use in conjunction with the fuel injection mechanism described and claimed in my copending application Serial No. 274,178, filed February 29, 1952.

However, this fuel injector nozzle is also equally useful in many other fuel injection or liquid injection systems.

Referring now to the drawings, reference 5 designates generally afuel injector nozzle assembly constructed in accordance with this invention, and assembled in position on an engine or motor block 6, shown fragmentarily,

2,719,055 Patented Sept. 27, 1955 the block 6 being chambered at 7 to provide a piston chamber or cylinder. Block 6 is also provided with an aperture 8 which communicates at its inner end with the piston chamber 6 and which is internally threaded to receive and threadably engage a correspondingly threaded forward portion of the fuel injector nozzle 5. Fuel line 9, connected at one end to the outer end of the nozzle assembly 5, may be connected to any suitable source of fuel pressure (not shown).

The fuel injector nozzle should accomplish, ordinarily, two functions: in the first place the nozzle must provide an atomized mist or spray of fuel in order to produce proper distribution of the fuel in the piston chamber. To the extent that this is accomplished, better burning characteristics are obtained from the fuel. In the second place, the nozzle must serve as a check valve so that during the explosive burning of the fuel, escape of fuel from the piston chamber through the nozzle is entirely prevented, while on the intake stroke, free flow of fuel past the check valve portion of the fuel injector nozzle assembly is assured. The fuel injector nozzle 5 of this invention provides both of these desirable operating characteristics.

The nozzle assembly 5 comprises an axially apertured housing 10 of generally cylindrical configuration, the forward portion of which is peripherally threaded to threadably engage the internally threaded wall of the aperture 8 formed in the side of the engine cylinder block and communicating with the piston chamber 7. A mounting flange 11 is integrally formed about the periphery of the mid-portion of the housing 10 and when the nozzle 5 is assembled on engine block 6 the left side of the flange 11 seats against the outer surface of the engine block or against a suitable washer sandwiched therebetween, as shown. The right end portion of the nozzle housing 10 is also threaded peripherally to receive and engage a cup shaped cap or closure member 12 which is provided with a flared axial aperture 13 to receive and embrace the flared left end 9a of the fuel line 9. When the cap is secured in position, the end 9a of the line 9, is pressed tightly against the tapered right end 10a, as viewed in Fig. 1, of the housing 10 to provide a fluid tight connection.

The axially apertured housing 10 defines therewithin an elongated cylindrical chamber 14, within which is located a valve 15 shown in detail in Fig. 2. Valve 15 is arranged to permit fluid pressure entering the chamber 14 from the right or inlet end to pass through the chamber and to be emitted through a restricted orifice or discharge port 16 formed in the left end of housing 10. When the nozzle 5 is assembled on the engine block 6, the discharge port 16 is then located in the aperture 8 and having its outer end protruding into the piston chamber 7. The valve 15 is slidably journalled in and axially shiftable in chamber 14 and in closed position seats on a valve seat 17, defined by the left edge of a ring 18, securely mounted against the inner periphery of the housing wall and located substantially in a transverse plane with the housing mounting flange 11. Ring 18 may, for example, be externally threaded to threadably engage a suitably threaded and shouldered portion 14a of the chamber 14. 1

In more detail the valve 15 comprises a main body portion 20, the right end of which is beveled or tapered to provide a valving surface 21 cooperable with the valve seat provided by the ring 18. Extending axially to the right from the valving surface 21 is a stem 22, the stem 22 extending through the valve seat ring 18 and having a small spring retaining washer 23 mounted transversely at its right end, as viewed in Fig. 1. Washer 23 is secured in position on the end of the stem 22 by a rivet 24 or by heading over the end of the stern. A spring 25 dis posed about the stem 22 bears at its left end against the right side of the ring 18 and at its right end against the left side 'of the washer and thus urges the valve into seated relation with respect to the valve seat 17 to prevent flow of pressure from the discharge orifice 16 backward through the nozzle to the line 9.

When pressure is supplied to the nozzle assembly 5, from the supply line 9, the valve 15 shifts to the left, the spring being made relatively light as compared to :the pressures of the fluid or fuel normally used. In order to provide a passage for pressure, the body portion 20 of the valve is made generally rectangular in crosssection, the corners of the rectangular body portion being rounded as indicated at 20a to provide a desirable bearing relation with the wall of chamber 14, and the flat sides 20b defining with the adjacent wall of the chamber 14 four longitudinally extending passages of su'fiicient combined size to provide an adequate path for the fuel.

In order to prevent the valve body from obstructing the passage of fuel by seating against the left end wall of the chamber, there are provided, preferably on the valve body, protuberances or stops 26, which may be integrally formed with the left side of the valve body portion 20 and which extend sufficiently to the left to space the left end of the body portion 20 from the adjacent wall of the chamber 14 when the valve is fully open. Thus when the valve is shifted fully to the left, there is still provided an adequate path for fluid to the discharge orifice 16.

To provide improved distribution of the fuel and to further restrict the discharge orifice, there extends from the left side of the body portion 20 of the valve 15, a rod-like pin or stem 27. This stem 27 extends into the orifice 16 and is made to have a lesser external diameter than the internal diameter of the orifice 16 whereby when the stem is located in the orifice, an annular passage is provided for fuel, the stem being located substantially concentrically with respect to the orifice. By selecting the relative dimensions of the orifice and of the stern cross-section, the effective size of the discharge orifice may be closely controlled. Further, it will be evident that because of the reciprocating movement of the valve stem 27 with respect to the orifice 16 during the operation of the nozzle assembly, any clogging of the orifice is substantially prevented, and the nozzle is, in effect, selfcleaning.

A particular feature of the present invention is the provision in the fuel injector nozzle of means to increase the turbulence of the fuel as it is discharged from the restricted orifice 16. This is accomplished in accordance with the present invention by providing at least one groove 30 which may be preferably formed about the periphery of the stem 27 and is so located that when the valve 15 is shifted to open position, the groove 30 is located as illustrated in Fig. 3.

It has been found, in practice, that the groove 30, interrupting as it does the otherwise smooth longitudinal configuration of the discharge orifice passage, greatly increases the turbulence of the discharge. This in turn provides better distribution of the fuel in the piston chamber than is obtained without such increased turbulence. Prior art devices of this general type, employing, however, a flanged head on the end of the stem to provide distribution do not provide the turbulence afforded by the arrangement of the present invention and have been found to tend to seat even during injection due to the venturi effect. Due to the width and location of the groove 30 in injecting position, the venturi effect is minimized. In addition, the reciprocating action of the stem and particularly of the groove with respect to the nozzle tip makes this injector nozzle largely self-cleaning.

Where herein the various elements of the fuel inject-or nozzle of this invention have been referred to as being located in a right or a left position, it will be understood that this is done solely for the purpose of facilitating description, and that the references relate only to the par- 4 ticular positions occupied by the parts as shown in the drawings.

While but one embodiment of this invention has been shown and described, it will be understood that many changes and modifications may be made therein without departing from the spirit or scope of the present invention.

What is claimed is:

l. A fuel injector nozzle including a generally cylindrical housing having a chamber formed therewithin and an inlet opening formed at one end and a discharge orifice formed at the opposite end, a longitudinally shiftable valve journalled in said chamber, a valve seat provided in said chamber intermediate said orifice and said opening and arranged to cooperate with said valve to prevent passage of fuel from said orifice to said opening, and a stern portion on said valve extending into said orifice but having a lesser external dimension than said orifice whereby to provide an annular passage for fuel, said stern portion having an annular groove generally rectangular in cross section formed about the periphery thereof and located when said valve is in open position at least partially outside of said orifice to increase the turbulence of fuel passing through said orifice.

2. A fuel injector nozzle comprising a nozzle housing having a chamber formed therein and an inlet opening communicating with one end of said chamber and a discharge orifice communicating with the opposite end of said chamber, means located intermediate said opening and said orifice defining a valve seat, a valve located in said chamber and adapted to cooperate with said valve seat to prevent communication from said orifice through said chamber to said opening when said valve is seated, resilient means for urging said valve towards seated position, said valve having a generally rectangular crosssection, the corners being arranged to engage in sliding relation the inner wall of said chamber, the flat sides of said valve providing passages when said valve is open to permit fuel to pass through said chamber to said orifice, spacer elements on said valve end adjacent the discharge end of said chamber for preventing said valve when not seated on said seat from obstructing said discharge orifice, and a stern portion on said valve extending into said orifice and having a lesser external dimension than the size of said orifice opening whereby to provide an annular passage for fuel, said stern portion having an annular groove generally rectangular in cross section formed about the periphery thereof and so located on said stern that when said valve is shifted to open position the groove is located at least partially outside of said orifice, whereby to increase the turbulence of the fuel passing through said annular passage.

3. A fuel injector nozzle comprising a nozzle housing having a chamber formed therein and an inlet opening communicating with one end of said chamber and a discharge orifice communicating with the opposite end of said chamber, means located intermediate said opening and said orifice defining a valve seat, a valve located in said chamber and adapted to cooperate with said valve seat to prevent communication from said orifice through said chamber to said opening when said valve is seated, resilient means for urging said valve towards seated position, said valve having a generally rectangular crosssection, the corners being arranged to engage in sliding relation the inner wall of said chamber, the fiat sides of said valve providing passages when said valve is open to permit fuel to pass through said chamber to said orifice, and a stem portion on said valve extending into said orifice and having a lesser external dimensionthan the size of said orifice opening whereby to provide an annular passage for fuel, said stem portion having an annular groove generally rectangular in cross section formed about the periphery thereof and so located on said stem that when said valve is shifted to open position the groove is located at least partially outside of said orifice, whereby to increase the turbulence of the fuel passing through said annular passage, and when said valve is shifted to closed position, the groove is located within said orifice, whereby the reciprocating action during the operation of the nozzle tends to make the nozzle self-cleaning.

4. A fuel injector nozzle comprising a nozzle housing having a chamber formed therein and an inlet opening communicating with one end of said chamber and a discharge opening communicating With the opposite end of said chamber, means located intermediate said two openings defining a valve seat, a valve located in said chamher and adapted to cooperate with said valve seat to prevent communication from said discharge opening through said chamber to said inlet opening when said valve is seated, resilient means for urging said valve toward seated position, spacer elements associated with said valve end adjacent the discharge opening of said chamber for preventing said valve from obstructing said discharge opening during the operation of said nozzle, and a stem portion of said valve located in said discharge opening Whereby to define therewith an annlar passage for fuel, said stem portion having a uniform cross sectional dimension throughout its entire length and having an annular groove of rectangular cross section, said groove being further particularly characterized by the feature that said groove is so located on the stem that when said valve is shifted to open position the groove is located at least partially outside of said discharge opening whereby to increase the turbulence of fuel passing thereout and when said valve is shifted to closed position the groove is located within said passage.

References Cited in the file of this patent UNITED STATES PATENTS 1,898,325 Venn Feb. 21, 1933 2,017,028 Heinrich Oct. 8, 1935 2,351,965 Hoffer June 20, 1944 FOREIGN PATENTS 902,982 France Jan. 5, 1945 908,955 France Nov. 12, 1945 

